Paradoxical brain embolism caused by pulmonary arteriovenous fistula and coincident pulmonary embolism--a case report

The authors encountered a very rare case of paradoxical brain embolism resulting from pulmonary arteriovenous fistula and coincident pulmonary embolism. Enhanced computed tomography was useful for diagnosing this infrequent condition.     

肺动脉血栓切除术治疗急性危重肺动脉栓塞症-单中心45例报告

目的 探讨肺动脉血栓切除术在急性危重肺动脉栓塞症（Pulmonary embolism,PE）治疗中的作用。方法 收集了我院2010年-2018年行肺动脉血栓切除术的45例急性危重PE患者的临床资料,比较患者术前、术后及随访期间的心脏彩超右心室直径、右心房直径、三尖瓣返流压差、肺动脉直径,比较术前、术后的动脉血氧分压（PaO2）、动脉血氧饱和度（SaO2）。结果 45例急性危重PE患者中3名术前心脏骤停的患者术后因严重缺血缺氧性脑病、多器官功能衰竭死亡或放弃治疗。其余42例病人均存活,随访期间无死亡病例（存活率93.3%,中位随访时间32月）。术后患者的PaO2、SaO2均高于术前（P<0.05）;术后、随访期间末次超声的右心房直径、右心室直径、三尖瓣返流压差、肺动脉直径均较术前明显减小（P<0.05）。结论 对于急性危重PE患者,肺动脉血栓切除术是一种安全的手术方式,死亡率低,可显著改善患者右心室功能及肺动脉压力,中远期效果良好。对于大面积肺动脉栓塞的危重患者,应该更为积极的考虑进行肺动脉血栓切除术。     

Thrombolysis with reteplase in acute pulmonary embolism

ObjectiveReteplase (recombinant plasminogen activator) is a mutant of alteplase. It has a longer half-life than its parent molecule and has shown better vessel patency rates in acute myocardial infarction. In this study, we analyzed the efficacy and safety of reteplase in acute pulmonary embolism (PE).MethodsThis observational study included patients with high- and intermediate-risk acute PE, presenting within 14 days of symptom onset. The patients were treated with reteplase, which was given in two bolus doses of 10 U each, 30 min apart, along with intravenous heparin. Patients with hemodynamic compromise (high-risk or massive PE) and normotensive patients with evidence of right ventricular (RV) dysfunction (intermediate-risk or submassive PE) on echocardiography or computed tomography were included in the study. The efficacy outcomes assessed were in-hospital death and improvement of RV function by echocardiography. The safety outcomes were major bleeding, minor bleeding, and ischemic or hemorrhagic stroke during hospitalization.ResultsOf the 40 patients included, 25% were classified as high risk with hemodynamic compromise and 75% were classified as intermediate risk. RV dysfunction was present in all the patients (100%). Concomitant lower extremity deep vein thrombosis was present in 55% of the patients. The mortality rate was 5%. There was significant improvement in RV function and reduction in pulmonary artery systolic pressure and tricuspid regurgitation severity. There was no major bleeding event or stroke, and 7.5% patients had minor extracranial bleeding.ConclusionsDouble-bolus reteplase given with heparin is effective in the treatment of high- and intermediate-risk PE, with minimal risk of bleeding.     

Negative D-dimers and peripheral pulmonary embolism

The measurement of D-dimers is a recent addition to the diagnostic strategy of pulmonary embolism and has been shown to be a valuable tool with excellent sensitivity. However, there have been rare reports of patients with pulmonary embolism but negative D-dimer tests. The object of this study was to study patients with pulmonary embolism but negative D-dimers and to compare them with a population of patients with pulmonary embolism and raised D-dimers. One hundred and fifty consecutive patients admitted for pulmonary embolism were included in this study. All underwent measurement of D-dimers (normal <500 ng/ml) by an ELISA technique. The data of clinical examination and complementary investigations were analysed with respect to the D-dimers result. The sensitivity of raised D-dimers for pulmonary embolism was 96% (6 patients had results <500 ng/ml). The finding of chest pain was statistically greater in the group with negative D-dimers (p=0.01). In these cases, the emboli were all distal (p=0.0003), the average Miller index was significantly lower than in patients with high D-dimers (p=0.04) and the diagnostic value of ultrasound investigations (echocardiography, ultrasonography of lower limb veins) was less (p<0.0001). The authors conclude that measurement of D-dimers by the ELISA method may be non-diagnostic in distal pulmonary embolism and one explanation could be the less extensive thromboembolic process. In cases with negative D-dimers, a strong clinical suspicion of pulmonary embolism should lead to the request for further investigations.     

Paradoxical brain embolism with Klippel-Trenaunay syndrome

Cerebrovascular diseases in patients with Klippel-Trenaunay Syndrome (KTS) are uncommon, and the mechanism of stroke has remained elusive. We describe a patient with KTS who experienced a transient ischemic attack (TIA). Contrast-transcranial Doppler with the Valsalva maneuver revealed a right-to-left shunt and contrast-transesophageal echocardiography confirmed patent foramen ovale. Ultrasonography revealed dilated superficial and deep veins in the lower extremities; the D-dimer level was high and indicated hypercoagulability. Therefore, the mechanism of TIA was diagnosed as paradoxical embolism. To the best of our knowledge, this is the first case report of paradoxical embolism in a patient with KTS.     

Predictive value of D-dimer test for recurrent venous thromboembolism at hospital discharge in patients with acute pulmonary embolism

D-dimer can be used to exclude acute pulmonary embolism (PE) for its high negative predictive value (NPV). Also, it is a predictor of recurrent venous thromboembolism (VTE) after anticoagulation withdrawal. The aim of the present study was to assess the predictive value of D-dimer for recurrent VTE when tested at hospital discharge. Plasma D-dimer levels were repeatedly measured at hospital discharge in 204 consecutive patients with the first episode of acute pulmonary embolism. Patients were categorized to two groups by D-dimer levels at hospital discharge and followed up at 3, 6, and 12 months and yearly thereafter. The primary end point was symptomatic, recurrent fatal or nonfatal VTE. D-dimer levels were persistently abnormal in 66 patients (32%). After 31±19 months follow-up, patients with persistently abnormal D-dimer level levels showed a higher rate of of recurrent VTE (14 patients, 21%) compared to those with D-dimer regression (8 patients, 6%) (P = 0.001). At the multivariate analysis, after adjustment for other relevant factors, persistently abnormal D-dimer level levels were an independent predictor of recurrent VTE in all subjects investigated, (hazard ratio, 4.10; 95% CI, 1.61–10.39; P = 0.003), especially in those with unprovoked PE (hazard ratio, 4.61; 95% CI, 1.85–11.49; P = 0.001). The negative predictive value of D-dimer was 94.2 and 92.9% in all subjects or those with unprovoked PE, respectively. Persistently abnormal D-dimer level levels at hospital discharge have a high negative predictive value for recurrence in patients with acute pulmonary embolism, especially in subjects with an unprovoked previous event.